Alessio Gomiero

The use of protozoa in ecotoxicology: Application of multiple endpoint tests of the ciliate E. crassus for the evaluation of sediment quality in coastal marine ecosystems

Despite an increasing number of surveys describing adverse effects of contaminated sediments on marine organisms, few studies have addressed protists. In this study, the free-crawling marine ciliate Euplotes crassus was evaluated as the test organism for the screening of sediment toxicity using sediments from both coastal and estuarine sites of the Venice Lagoon (Marghera harbour [MH], Valle Millecampi [MV], Murano island [MI] and Lido inlet [LI]). Two endpoints of high ecological value, mortality (Mry) and replication rate (RpR), were assessed in combination with the two sublethal biomarkers of stress, endocytotic rate (Ecy) and lysosomal membrane stability (NRRT). The results showed a significant inhibition of RpR, Ecy and NRRT paralleled by a small and insignificantly increased Mry of the exposed specimens. Our results thus demonstrate that only a combination of mortality and sublethal biomarkers was able to characterise an exposure-related stress syndrome. The suite of biomarkers described here was also able to detect and resolve a pollution-induced stress syndrome at an early stage of pollution. The contamination level of the sediments was assessed using chemical analysis, by estimating bioavailability and by computing a toxic pressure coefficient (TPC) to account for potential additive effects of different pollutants. The observed biological responses were consistent with the contamination levels in sediments, suggesting a high potential for using Protozoa in bioassays to assess environmental risk in coastal marine systems.

Integrated use of biomarkers in the mussel Mytilus galloprovincialis for assessing off-shore gas platforms in the Adriatic Sea: Results of a two-year biomonitoring program

Despite a large number of gas platforms existing in the Adriatic Sea, which is a semi-enclosed basin characterized by a slow turnover rate and increasing industrial as well as other anthropogenic activities, the effects of these structures on the aquatic ecosystem require further investigation. Since 1998, multidisciplinary studies have been performed by CNR-ISMAR to comply with legislation and to support the development of protocols for the monitoring of offshore activities in the Adriatic Sea. The present study was developed to implement a biomonitoring plan to assess the ecotoxicological effects of the extraction activities of an off-shore gas platform. Biomarkers were evaluated in mussels collected from the platform in relation to physiological stress, DNA damage, cellular damage, oxidative stress and exposure effects. Organic contaminants and trace element bioaccumulation were also assessed in the soft body of the mussels to correlate bioaccumulation of pollutants with biomarker responses. The results indicate an absence of platform-related environmental stress.

A multidisciplinary approach to evaluate the environmental impact of offshore gas platforms in the western Adriatic Sea

Detecting the anthropogenic impacts of offshore gas platforms requires reliable tools, because the traditional evaluation based only on chemical analyses is neither appropriate nor sufficiently sensitive. Thus, a 3-year monitoring project was carried out to evaluate the impact of a platform based on a chemical–biological approach. Benthic communities are investigated as they are widely used to monitor the effects of marine impacts because the organisms are mostly sessile and integrate the effects of pollutants over time. Changes in benthic infauna, sediments and water quality, as well as biota bioaccumulation, caused by drilling and platform operations were evaluated experimentally. Furthermore, mussels (Mytilus galloprovincialis) were collected seasonally from the platform legs, both close to and far from the sacrificial anodes and at a control site. Responses of biomarkers of exposure and effect were related to the average levels of polycyclic and aliphatic hydrocarbons, organic matter content and heavy metals in bivalve tissues. Our data suggested that a slight perturbation can be detected only by integrating the results of chemical analyses on water and sediments and those obtained from benthic biological surveys.

Development of an integrated chemical, biological and ecological approach for impact assessment of Mediterranean offshore gas platforms

The pressure for more energy demand is a strong driver for the construction of offshore oil and gas platforms. This also applies to the Adriatic Sea where, since 1960, several gas fields have been commissioned. The continuous expansion of the gas industry may potentially have detrimental effects on marine communities. This may become particularly clear in such a peculiar semi-enclosed basin as the Adriatic Sea, which contains ecosystems that are subject to intensive anthropic pressures, such as unsustainable fishing and inputs of environmental pollutants. To date, still scant information is available on the environmental effects of gas platforms. Thus, to comply with the national Italian legislation and to support the development of protocols for the monitoring of offshore activities, multidisciplinary studies have been conducted and performed by CNR-ISMAR in cooperation with some private and public research institutes. A multidisciplinary approach based on chemical, biological and ecological investigations was performed to evaluate both the water column and the sediment quality near a gas platform. The overall results indicate moderate effects of platform-related environmental stress.

Use of multiple cell and tissue-level biomarkers in mussels collected along two gas fields in the northern Adriatic Sea as a tool for long term environmental monitoring.

As a consequence of the growing global demand of energy supplies, intense oil and gas exploration and exploitation programs have been carried out worldwide especially within the marine environments. The release of oil-derived compounds in the sea from anthropogenic sources both as effluents or accidental spill is perceived as a major environmental concern. An approach based on a combination of biomarkers and the distribution of some classes of environmentally relevant pollutants was used to investigate the occurrence of a stress syndrome in mussels (Mytilus galloprovincialis) collected at three gas platforms placed in two distinct oceanographic districts within the Adriatic Sea. Biological responses were integrated by a ranking algorithm which demonstrated both a range of biological effects reflecting exposure gradients and a temporal related trend in the investigated responses. The overall results demonstrate a moderate to absent pollution from studied gas platforms with low but remarkable biological disturbance in sentinel organisms.

Comparative Effects of Ingested PVC Micro Particles With and Without Adsorbed Benzo(a)pyrene vs. Spiked Sediments on the Cellular and Sub Cellular Processes of the Benthic Organism Hediste diversicolor

The plastic microliter represents an emerging contaminant as well as multiple stress agent in the aquatic environments. Microplastics are found even in the remote areas of the world. Together with their occurrence in all environmental compartments, there is a growing concern about their potential of adsorbing pollutants co-occurring in the environment. Currently, little is known about this source of exposure for aquatic organisms in the benthic environment. Exposure conditions were set up mimicking the contribution of microplastics in different exposure routes. The potential biological effects were investigated in the model organism: the annelid Hediste diversicolor. Cellular effects including alterations of immunological responses, lysosomal compartment, mitochondrial activity, oxyradical production and onset of genotoxicity were assessed in coelomocytes while temporary and permanent effects of oxidative stress were also performed at tissue level. In this study polyvinylchloride (PVC) microplastics were shown to adsorb benzo(a)pyrene with a time and dose-dependent relationship. Results also indicated a marked capability of contaminated microplastics to transfer the model organic chemical to exposed model organism under physiological gut conditions and concentrated in tissues. The elevated bioavailability of the model pollutant after the ingestion induced a clear pattern of biological responses. Toxicity mainly targeted impairment of cellular functioning and genotoxicity in ragworm’s coelomocytes, while permanent effects of oxidative stress were observed at tissue level. Coelomocytes responded faster and with a higher degree of sensitivity to the adverse stimuli when compared with responses observed in whole tissue samples. The results showed that microplastic particles in sediments may play a significant role as vectors for organic pollutants. The highest adverse responses were observed in those ragworms exposed to sediments spiked with PVC particles pre-incubated with B[a]P when compared against sediments spiked with B[a]P and microplastics separately.

Plastic Soles: Microplastic Litter in the Gastrointestinal Tract of Solea solea from the Adriatic Sea

Plastic is widely used in everyday life being one of the more versatile materials ever produced. The rising demand of plastic items to support the societal development has dramatically boosted the annual plastic production from 1.5 in the 1950s to 311 million tonnes in 2014 (PlasticEurope in Plastic-the Facts 2015: an analysis of European plastic production, demand, and waste data, 2014). The dark side of the plastic revolution is the marine pollution, with an estimated amount of 9.5 million tonnes of new plastic waste flowing into the oceans each year (Boucher and Friot in Primary microplastics in the oceans: a global evaluation of sources. IUCN, Gland, p. 43, 2017).

Environmental Impact of Offshore Gas Activities on the Benthic Environment: A Case Study

Multidisciplinary monitoring of the impact of offshore gas platforms on northern and central Adriatic marine ecosystems has been conducted since 1998. Beginning in 2006, 4–5 year investigations spanning the period before, during, and after rig installation have explored the effects of its construction and presence on macrozoobenthic communities, sediment, water quality, pollutant bioaccumulation, and fish assemblages. In this study, sediment samples collected at increasing distance from an offshore gas platform before, during and after its construction were subjected to chemical analysis and assessment of benthic communities. Ecological indices were calculated to evaluate the ecological status of the area. Ecotoxicological analysis of sediment was performed to establish whether pollutants are transferred to biota. The study applied a before–after control-impact design to assess the effects of rig construction and presence and provide reference data on the possible impacts of any further expansion of the gas extraction industry in the already heavily exploited Adriatic Sea. Only some of the metals investigated (barium, chromium, cadmium, and zinc) showed a different spatial and/or temporal distribution that may be platform-related. In the early phases, the sediment concentrations of polycyclic aromatic hydrocarbons were below the detection limit at all sites; they then became detectable, but without significant spatial differences. The present findings suggest that the environmental effects of offshore gas platforms may be difficult to quantify, interpret, and generalize, because they are influenced by numerous, often local, abiotic, and biotic variables in different and unpredictable ways.